This application relates to an electric system for a generator in a gas turbine engine, which generates power for both a related aircraft through a power bus, and engine accessories through an accessory bus. A switch is opened in the event of a detection of a short circuit on the aircraft power bus to disconnect the bus from the engine accessories. Thus, the engine accessories can continue to be driven.
A power generating system converts motive power generated by a prime mover, such as gas turbine engine to DC electrical power that is supplied to a DC bus to which various aircraft electrical components may be connected.
Recently, electric engine architecture has been developed which includes an integrated generator associated with a gas turbine engine. Power generated by the generator flows to an aircraft power bus and, also to a plurality of engine accessories. Thus, the engine accessories are powered directly by the generated electric power and the power for other aircraft functions is also supplied from the generator. The power bus and the accessories are in parallel relative to each other.
There is a potential with this arrangement that a short circuit on the power bus can divert power from the engine accessories. In addition, a voltage regulator for controlling the voltage flowing from the generator will receive no control voltage in the event of a short circuit. In the known system, the control voltage is received from the power bus. However, in the event of a short circuit, there would be no control voltage.
In the prior art, it is also known to provide a control permanent magnet generator in addition to a wound coil main generator in the gas turbine engine. Power generated from the control permanent magnet generator is delivered to a voltage regulator for the wound coil generator. This arrangement has not been utilized in a system wherein there are engine accessories provided with power in parallel to a power bus, nor where the main generator is a permanent magnet generator.